| Value | Category |
|---|---|
| 0 | end of list |
| 1 | not frequent enough |
| 2 | stops are far away |
| 3 | no night service |
| 4 | vehicles carriages are in bad condition |
| 5 | no schedule or schedule is not followed |
| 6 | fares are too expensive |
| 7 | too crowded |
| 8 | too slow |
| 9 | other |
| 10 | no problem |
| Sysmiss |